#include "cube3d.h"

static void	init_raycast(t_rcast *rcast, t_vec *ray)
{
	rcast->is_x = 0;
	// ray sign
	rcast->ray_sign_x = 1;
	if (ray->start.x < ray->end.x)
		rcast->ray_sign_x = -1;
	rcast->ray_sign_y = 1;
	if (ray->start.y < ray->end.y)
		rcast->ray_sign_y = -1;
	// cell position of ray
	rcast->cell_x = ray->start.x / rcast->cell;
	rcast->cell_y = ray->start.y / rcast->cell;
	// slope of ray
	rcast->slope_x = ray->end.x - ray->start.x;
	rcast->slope_y = ray->end.y - ray->start.y;
	// direction of next cell
	rcast->next_cell_x = -rcast->ray_sign_x;
	rcast->next_cell_y = -rcast->ray_sign_y;
	// ray steps in both axis
	rcast->ray_step_x = 0;
	if (rcast->slope_x)
	{
		rcast->ray_step_x = ft_abs(rcast->cell);
		if (rcast->slope_y)
			rcast->ray_step_x *= ft_abs(rcast->slope_y);
	}
	rcast->ray_step_y = 0;
	if (rcast->slope_y)
	{
		rcast->ray_step_y = ft_abs(rcast->cell);
		if (rcast->slope_x)
			rcast->ray_step_y *= ft_abs(rcast->slope_x);
	}
	
	// tmp
		if (rcast->tmp)
			printf(" [slope_x:%i, slope_y:%i]", rcast->slope_x, rcast->slope_y);
	//tmp

}

static void	init_first_step(t_rcast *rcast, t_vec *ray)
{
	rcast->first_next_x = 0;
	if (rcast->slope_x)
		rcast->first_next_x = ray->start.x % rcast->cell;
	if (rcast->ray_sign_x < 0)
		rcast->first_next_x -= rcast->cell;
	rcast->first_next_y = 0;
	if (rcast->slope_y)
		rcast->first_next_y = ray->start.y % rcast->cell;
	if (rcast->ray_sign_y < 0)
		rcast->first_next_y -= rcast->cell;
	rcast->next_x = ft_abs(rcast->first_next_x);
	if (rcast->slope_y != 0)
		rcast->next_x *= ft_abs(rcast->slope_y);
	rcast->next_y = ft_abs(rcast->first_next_y);
	if (rcast->slope_x != 0)
		rcast->next_y *= ft_abs(rcast->slope_x);

	// tmp
		if (rcast->tmp)
			printf(" [next_x:%i, next_y:%i]", rcast->next_x, rcast->next_y);
	//tmp

}

static void	next_cell(t_rcast *rcast)
{

	// tmp
		if (rcast->tmp)
			printf("\n [next_x(%i) > next_y(%i) ?]", rcast->next_x, rcast->next_y);
	//tmp

	if (!rcast->slope_x || (rcast->next_x > rcast->next_y && rcast->slope_y))
	{
		rcast->cell_y += rcast->next_cell_y;
		rcast->next_y += rcast->ray_step_y;
		rcast->is_x = 0;

	// tmp
		if (rcast->tmp)
			printf(" [yes] (increase y by %i)", rcast->ray_step_y);
	//tmp

	}
	else
	{
		rcast->cell_x += rcast->next_cell_x;
		rcast->next_x += rcast->ray_step_x;
		rcast->is_x = 1;

	// tmp
		if (rcast->tmp)
			printf(" [no] (increase x by %i)", rcast->ray_step_x);
	//tmp

	}
}

void	ray_intersect(t_game *game, t_rcast *rcast, t_vec *ray)
{
	ray->start.x = rcast->ray.start.x + game->plr.pos.x;
	ray->start.y = rcast->ray.start.y + game->plr.pos.y;
	ray->end.x = rcast->ray.end.x + game->plr.pos.x;
	ray->end.x += rcast->ray_nb;
	ray->end.y = rcast->ray.end.y + game->plr.pos.y;
	rotate(&(game->plr), &(ray->end));

	// tmp
		rcast->tmp = 0;
		if (ray->end.x - ray->start.x == 0)
			rcast->tmp = 1;
		if (ray->end.y - ray->start.y == 0)
			rcast->tmp = 1;
		if (rcast->tmp)
			printf("[ray nb : %3i]", rcast->ray_nb);
	//tmp end

	init_raycast(rcast, ray);
	init_first_step(rcast, ray);
	while (!is_wall(game, rcast->cell_x, rcast->cell_y))
		next_cell(rcast);

	// tmp
		if (rcast->tmp)
			printf("\n");
	//tmp end

}